Opus BT-C3100 v2.2 4 Bay Digital Battery Charger

Nice charger I use my batteries for a vape device and they get very hot they seem too last longer after being charged here and not the device I love the refresh feature great buy!!

Great charger. Lots of info available while charging.

I really like this vendor. Excellent inventory, same day shipping, and great follow up.

Cats Meow of reasonable 18650 with chargers !!

This charger is easy to use. When I insert a battery, the first thing you can set is the charge rate if you are not using the default. But the modes are handy as well. Not thinking I need all the settings, I find having them came in handy for different batteries.

Thanks for the free flashlight!

Amazing product not sure what people's deal with the little fan was i cant even hear the thing its very quiet does everything it says and well worth the extra few bucks for the extra features it offers

Picture shows block of 18650 batteries done with my Opus charger !!

Love this charger. I would expect to pay much more fore this feature filled item.

Cooling fan sounds like its about to die straight out of the box, everything else is good

This is my 4th Opus charger. Not that I had any major problems with any of them, except on my first one, which is about 2 years old now, the fan started to make noise after about 6 months, but all you have to do is add a drop or two of light oil (Wahl clipper oil) to the sleeve bearing to make it quiet again. It literally takes 5 minutes to do. Remove the 4 screws on the bottom of the charger. Use a small jewelers screw driver to carefully pry out the fan, it's held in place with a couple drops silicone adhesive. Peel up the adhesive sticker on the fan enough to expose the fan shaft and bearing and add a drop of light oil. Then reassemble. Or if you really want to improve the cooling, you can do this. I removed the small fan and added a much larger fan to the bottom on all of mine. I've used 6800rpm 40mmx10mm and 4000rpm 50mmx10mm 12v 2 pin ball bearing fans to add much more efficient cooling without the need for 3D printing a new bottom. I removed some of the vents on the bottom using flush cut snips to open up the area where the fan is glued. The plastic bottom has just enough softness to it to make the process quite easy. Just be sure to secure the two center pins that hold the springs for the slides so they don't fall out when when you turn the charger right side up again. The bottom keeps them from falling completely out and one of the cross bars that make up the vents also serves that purpose. A spot of hot glue to the pin and circuit board works well. I use a drop of hot glue on each side of the fan to secure the fan to the bottom of the charger. You must also remove the plug socket for the stock fan from the 2 pin header to fully expose the 2 pins on the circuit board. Just pull it off carefully with small needle nose pliers. Take a picture with your phone so you know how to position the red and black wires, or mark the circuit board with a marker before unplugging the fan. Add something to the bottom of the charger to build up clearance so the fan has space to draw in air. I stacked a few pieces of high quality foam weather door seal. Warm up the adhesive before applying. The fan blows directly on the circuit board AND up through the slots in the slides. Works like charm! Way better than the stock fan! Oh yeah, make sure the charger works properly for a week or so before attempting this modification. I gave this last charger away as a gift to my neighbor for his kindness of plowing me out this winter. I modified this one too!

Easy to use and works as advertised.

This charger is everything I was hoping for and more. This unit gave me the capacity of all the cells that I had in my collection. It gave an indication of the state of my cells as well. For those who want to know the condition of their cells and want them to last as long as possible this is the charger for you.

Glad I bought 2

This thing is great. I had little 2 bay chargers that are hard to get the batteries in, and when I would remove the batteries they would go flying because the springs are too strong..... The batteries slide in and out of this easily. You are never left in the dark as far as where the charging process is, because it tells you, via a backlit, large print, easy to read display, how many volts the battery is holding. You can use it just to see if a battery is good, the stress of "I wonder if my batteries are any good?" Is a thing of the past. There is a cycle I haven't used yet, where you can drain the batteries and recharge as a sort of "reboot", that will come in handy some day. Its just an easy to use, efficient charger, I'm very pleased.

Works great for charging, testing capacity and refreshing li-ion batteries.

Shipping- Meet expectations Actual product- does everything thing its supposed to do but after a week fans are already screaming. I have been told it’s a know issue and just plan on having to replace them. One of the four units the backlight never cycles off after use. Not a deal breakers but annoying. Beware that even those these are not a batteries 18650store will not allow returns.

Perfect

great charger I like that each charging bay are on separate circuit

This is a wonderful unit. I love data that is being shown at all times and being able to adjust the charging rate.

Great chargers since you can test cells. Shipping was super fast, got to canada in 2 days. Very impressed with all the service I have gotten from this seller!

Sold Battery Charger with good features. The internal resistance measurement will help you determine whether your battery is too old to use even when it does still take a charge.

Very well made charger with a ton of features. The display is easy to understand and read and you don't have to scroll through each slot to see whats going on. Heat management is awesome with the fan that only comes on when needed. You can charge in one bay while refreshing in another at the same time. Small footprint so it fits in a small area of a desk or worktable. I have the Xtar Dragon VP4 Plus, which I love, but I prefer the Opus for the independent operating bays.

Working well, all the functionalities are available, I tested it with some batteries. The display has some problems, at the beginning the slot 3 and 4 were unreadable, I found that pushing the case beside slot 4 increase the display quality a lot. I put a tiewarp around the case to practically solve the problem.

It needs a better cooling system.

So far it’s working great. I like being able to select the charging current and having four slots where my old one had two. I haven’t tried all the functions yet.

This is a great, highly versatile charger/analyzer. I was a little concerned when this reading came up on a capacity test, but after I carefully removed the Sofirn wrap on the battery, it exposed the original manufacturers wrap which indicated is was a 3350mAh battery. Nice! Extremely fast shipping too! Will be placing orders here in the near future!

Works great with everything I've thrown at it.

Great charger! It has a lot of features that can show you exactly what your batteries are doing and the condition. Takes a little bit of reading and research to learn how to use it properly. But a simple YouTube search will answer all your questions about this charger.

Works well

Works, took a while to get to me but we can attribute that to the pandemic. Product is amazing.

this is my second opus charger. they're amazing. it's my second because I accidentally threw away my first when the transformer died. great charger. this site is good, too. shipped fast

Clocked in at 2700 mAh for the Molicel! Got it on deal of the day. Amazing little beast!

this is the best charger i have owned charges all batteries not just vape batteries good price

Works as advertised. Convenient to use.

Works very well and simple to use. Brought countless batteries back to life with plenty of power to use. Highly recommend

Great charger for those of us that want to know all the info! You won’t find a better charger in this price point period.

Good quality, fast deliver. All you can ask.

An unbelievably great charger!

Trabaja perfecto. Un poco complicado al principio. Muy versatil, tiene varias funciones que ayudan a identificar el estado de salud de las baterias.

Great charger for a great price, and very fast shipping!

Es realmente muy útil.

Instructions are good and charger and discharger works well. It takes a long time to test the batteries for capacity but it worked very well . It is very easy to test internal resistance with this device .

While the documentation that comes with the charger is a bit skimpy and not that clearly written, once you uncover the features of the unit it is well worth the investment. The ability to 'reform' Li-Ion, and Ni-Cd batteries to restore capacity unattended is worth the price. The battery charge then discharge to measure capacity test repeats until peak capacity is reached. This can take over a day to complete. This charger will test four 18650s independently until each cell is optimized. This also will report the REAL measured capacity of a cell reached after multiple cycles. I was stunned at the variance on new 18650 batteries. A large percentage of 18650 batteries, and the AA sized Li-Ions coming out of China are totally fraudulent. Tests of 6 batteries purchased thru Amazon as "legitimate" are astoundingly consistent and horrible below labeled capacity. They are just plain BOGUS! Here is a list of Rated capacity/REAL Optimized Capacity results after refresh cycles to optimize capacity: BRAND (# Tested)-------RATING-------MEASURED CAPACITY and SOURCE EPOCH (2) 3500 ma 3251 - 3300 ma (~95% of rating) From 18650 store ALONEFIRE (2) 2000 ma 1617 - 1676 ma (~20% low) Came with flashlight UltraFire (6) 5000 ma ! 1398 - 1471 ma (~ 30% of rating) Source: AMAZON

It does what I want it to do, charge batteries.

Great charger. Easy to use. Ordered the 15, receved the 22 of december in canada. Wow!

Great charger. Love the individuality of each battery. You can charge one while discharging another. So much more.

Nicad, Nimh, Li-ion Charger Great price (was on sale), didn't look close enough, charges Nicad, Nimh, Li-ion but not LiFePO4. Otherwise seems ok so far.

Good Product ... Good Service .... Thank you Purchased this OPUS charger. It works as advertised. The manual could be better written but it's adequate. I've done enough comparisons to believe that the BT-C3100 V2.2 is identical to the BT-C3400 V3.1. In fact, if you purchase the BT-C3100 V2.2, that you go find (and use) the PDF manual for the BT-C3400 V3.1 . I recommend either unit. I can also recommend dealing with the 18650 Battery Store. Quick easy ordering, good price, fast delivery.

Great prices & fast delivery. I check every battery sold by 18650 battery Store, and they sell batteries equal to the numbers quoted. Plus, the Charger, was a great price.

Nice charger Great price on a great charger + fast shipping. Thanks!

Great charger Bought to replace the same charger, been great for the last several years but needed a new one

Battery charger Charger is working so far, and the price was below Amazon.

Nice Charger for NiMH, Lion, and NiCad batteries. Worked great right out of the box and reconditioned some older NiMH batteries that were (I thought) throwaways. They are working fine now. Great feature set and didn't take long to learn how to use them. Plenty of videos on YouTube if you need help. 18650 Batteries is a great place to get it at a great price. Couldn't be happier.

Excelent Great charger/analyzer easy to use

As expected Does everything you need.

Opus BT-C3100 Rocks!! Pretty good device. It's currently restoring all my salvaged 18650 cells for my ebike battery. It's easy to use and delivery was pretty quick too. I definitely recommend this product. I would advice anyone who is in a rush to "restore" a lot of old cells to buy multiple units as it can take a long time.

Great Charger! I especially like that it can accurately measure internal resistance and cell capacity, making it easy to sort out those batteries that are due for recycling.

Excellent battery charger This company have a fast service ! Good prices !

My first modern battery charger After watching a lot of YouTube videos I chose the Opus BT-C3100 v2.2 charger to replace my very old NiMh/NiCad charger. The Opus BT-C3100 had great reviews although I am still a little confused by the mixed messaging regarding similarities with the BT-C3400 v2.2. The prices were different but some sites suggested that the C3100 and the C3400 were identical. I cannot really compare the BT-C3100 against any other modern battery charger since this is my first purchase but I really like the ability to test batteries and to refresh them. The Refresh/Discharge mode can take a very long time (more than 1 day) to complete but that could be because of the age of some of my rechargeables. The only negative I have is that the cooling fan can be very noisy and does not like to be moved while running. I like this universal charger a lot and I plan to purchase more as presents.

Happy with Purchase On time delivery and product is as described.

Good product design, fast delivery This battery charger has some great features such as testing the capacity and managing the charge rate. It's the best value out there. I've now run a couple dozen batteries through it with good results. The fan is throttled and quiet when running. The sliding power bus bar allows easy and reliable connection for the variety of sizes accommodated. The 18650batterystore has delivered several packages to me with quick, well tracked service, they've earned a big Thank You.

Fast service Item in stock, shipped and arrived quickly.

Great charger and reconditioner The charger is perfect for my needs. It charges a wide range of batteries and it can recondition older batteries. There are also a great online communities for this charger if you have any questions.

Excellent Experience Price was right, shipping was fast, product exactly as described.

Very nice! Excellent charger. Current selectable for each slot. I use it primarily for testing recycled cells for capacity and internal resistance. The only improvement I would suggest is adjustable cut-off voltage but for the price it's perfectly suited for my needs.

Excellent Both chargers perform as advertised! Testing cells all day long!

Works great Simple interface, which is great for me since I'm just getting started with rechargeable battery projects. Don't need a bunch of bells and whistles.

Great charger/tester Works exactly as I would expect, the fan is quiet enough to not be that noticable. It does overheat if you're doing back to back to back battery tests and will stop to cool down automatically. I use a separate charger and use this just for testing and can run through a lot of batteries

Excelente The Best Charger

The best Charger When you're serious about your work, and testing batteries is part of it, you have to go with the best. Proven over and over again.

Opus charger Fast shipping, service online A+

Great charger It is a lot lighter than I thought; but since I saw reviews on YouTube, I knew what to expect; and indeed, it is a great charger. I had a couple of Energizer AA batteries, which its charger didn’t recognize anymore, I was able to get them back to work with this charger. Not 100%, but from the labeled 2000, I got back to 1400 after being dead for 2 years This charger didn’t disappoint Price here was lower than everywhere else

Opus BT-C3100 v2.2 I chose this Charger due to the reviews on laserpointerforums.com and I am glad I did. It charges a battery separately in each of the four bays. Works great.

Good experience Second order from 18650batterystore, fast shipping, good price. Would definitely buy from them again.

Happy with the Purchase... New to the rechargeable battery world. Was looking for a good charger that could be used with limited knowledge and with safety in mind. This one came recommended from several avenues. Happy with the purchase to this point.

Been looking for a charger like this for a while. This charger is good, accurately show the energy the battery can hold.

Versatile charger with good quality Got this mainly to charge 18650 Li-ION batteries, but have also charged 16340 Li-ION as well as Ni-MH & Ni-Cd batteries. The 'refresh' feature can restore old Ni-Cds with a 'memory'.

Opus BT-C3100 v2.2 Great product! and 18650BatteryStore is great.

battery charger Excelent item and fast delivery. AAA++++

battery charger Excelent item and fast delivery.

Nice Excellent charger

Great battery charger, at a good price! This bussiness was recommended by my son. Great price, great selection, order was processed fast and delivered on time. Will use the bussiness again in near future.

Best one Yet Works like a charm with accurate measurements.

BIG Performance, little price Great product for testing 18650 batteries !! Lowest price I could find on the net, and that is always a BIG plus !!

Charger/Tester Previously bought a Liito Kala Lii-500 that was DOA. After returning it, I got the Opus for just a little more coin. Well worth it. Have purged nine AA NiMH's and a No-name 18650 from my battery stash. None of them were completely dead, just weak. Am now headache free. Charging is as good/better than my Nitecore I4. If you use rechargeables, you need a testing means! This one is convenient and won't break the bank.

So far so good!! I haven't played with the switch because I only have NIMH and 18650 and also have an IMAX b-6 I use to put slcells into storage. Works well so far. Used it heavily and no issues. Fan can be loud but better than it overheating. All on all I like it. It's like my lacrosse bc-1000 and bc-700 but can do lithium ion as well :-)

Retired Electronics Unbelieveable and easy to use. I have pot loads of untested batteries and no idea of the "juice" inside. The individual slots are the key to this charger. I charged Li-ion with Nimh, AA with AAA at same time. Was able to label batteries and order them and dispose of weak units. Looked at several chargers and this one kept coming up. And a big plus was 18650 Batteries getting it to me in like a couple days. Thanks!!!!

The Opus BT-C3100 is much more than just a charger This is probably the best battery charger and tester on the market, it does everything I need it to do. I have two of them and I have two LiitoKala 500 series, they are also first rate. In addition to those four I have an XTAR Dragon and the Nitecore SC4. The Xtar has performed very well but I am having problems with the Nitecore. When charging 18650's it won't charge the first three bays to the same level as the forth bay. I am almost through processing 300 18650's to build large 12V batteries and I have had all these chargers working overtime. This is the second Nitecore I have had problems with. The folks at the 18650BatteryStore have been great to work with, they have some of the best prices around and deliver promptly.

Stuck on Opus I have an Opus BT-C3400 for my 18650 batteries and have been so impressed with it, when it was time to get a charger for my new 21700 batteries, it was a no-brainer. These are excellent chargers.

Get the Opus I bought the Opus BT-3100 v2.2 after watching video reviews as well as advice from friends. This does it all. Not only charges, but can test and tell you everything that's going on with your batteries. It accommodates 20700 and 21700 batteries easily. This is so much better than what you would get from your average vape store. Very easy to use too.

Great features. Purchased on the recommendation of others. For my purposes this charger provides all functions including testing and discharge etc. Good value and performance. Highly recommended.

Best charger I have found. I already had an Opus BT-C700 for Nicads & NiMhs & needed one for lithium 18650s. After researching what is available, I ordered the BT-C3100 V2.2. It works great! I like being able to monitor all the parameters such as voltage, charge or discharge current, MaHrs put it, etc. The voltage reading is a little low but the cutoff point seems to be 4.2V like it should be.